This is a proposal for a "Biomedical Research Support Shared Instrumentation Grant" (SIG) to upgrade the biomedical research instrumentation in the University of Alabama at Birmingham (UAB) Flow Cytometry Core Facility (FCCF). The primary purpose of the UAB FCCF is to make available to UAB biomedical investigators access to shared research instrumentation, trained personnel and expertise to perform cell analysis and purification with state-of-the-art instruments, software, and techniques on a reasonable cost for services basis. At the present time the FCCF contains a FACScan five parameter single laser analytical cytometer and a FACStar(plus) six parameter, dual laser cytometer/sorter. The heavy use of the FCCF by NIH supported investigators reflects the availability of good service and a variety of programs. However, operating efficiency has been compromised recently by old computer hardware for which replacement parts are not readily available, antiquated software which limits investigators' ability to analyze data, and more frequent laser failure. The proposed upgrade will: 1) Replace the operating and data acquisition computer hardware with Apple Macintosh Quadra 650's with Ethernet connections; 2) Replace existing software with CellQuest, the latest from Becton Dickinson, which is improved over current applications in having a single, integrated acquisition and analysis format, capability to cut and copy to other applications, selective printing, customized histograms, and an improved, faster filing system. Conversion from existing files acquired with other FACS software is included. We will also acquire software designed for automated analysis through dynamic gating (Attractors) and color dot plot analysis (Paint-a-gate). All software can communicate between stations; 3) Install a new workstation for independent analysis by users at any time without disruption of core operations; 4) Install a new split-beam laser, which will allow excitation at both 488 and UV from one laser; and 5) Install Sort Acceleration Modification for fluidics, electronics, and drop deflection control. This integrated package permits an increase in sort rates of almost an order of magnitude. Increases in the throughput and efficiency of the FCCF will result in better output at lower cost to investigators. Experiments which have not been possible for practical considerations now become possible, expanding the range of applications for the core facility. NIH support for the proposed upgrade will ensure that biomedical investigators based at UAB continue to have shared access to state-of-the-art cell sorting instrumentation and related systems.